Question about mama hen and babies

[Lrm93]

my hen hatched 9 eggs while I was away on vacation. My chicken sitter made sure they had started food available and such. The first day out of their nest, 1 baby died. The day we were coming home from vacation, 3 babies died. Now 2 days I've been home (I haven't been able to spend much time out there because of picking up my daughter and the dogs and trying to unpack), 2 more babies are dead this morning. My mama hen is very aggressive when I try to take her babies, but I don't think she's teaching them how to eat. It doesn't look like they have touched her food.
Mama is only 1 year old. She went broody and hid her nest so we didn't even know where she was. Is she too young to be a mother? This is our third mama hen we have had and the other 2 had very successful mama/chick relationships and all chicks survived. Is she just too young? I'm going to try to catch the babies but mama is very mean now. Any insight?

 

[azygous]

It's hard to come up with insight without more information. How warm, or cold, is it? Perhaps the chicks were stranded and couldn't warm under the broody and died of hypothermia. Is food and water handy on the ground/floor so the chicks can access it? How about the nest? Is it on the ground? Chicks might be able to get out of a high nest but not be able to get back up.

Is the nest in a secure place so wild animals or dogs or snakes can't eat the chicks?

 

[Lrm93]

It's hard to come up with insight without more information. How warm, or cold, is it? Perhaps the chicks were stranded and couldn't warm under the broody and died of hypothermia. Is food and water handy on the ground/floor so the chicks can access it? How about the nest? Is it on the ground? Chicks might be able to get out of a high nest but not be able to get back up.

Is the nest in a secure place so wild animals or dogs or snakes can't eat the chicks?

It's about 85° during the day and 65° at night. Mama made a nest on the ground floor inside the coop. No predators can get in. They have easy access to food and water.
We've never had such a young mama hen so I didn't know if maybe she just doesn't know what she's doing. I've never had chicks die that were hatched by mama

 

[azygous]

Did you examine the dead chicks to learn if they died from injuries? The other explanation would be poor genetics causing the chicks not to survive.